Improvement in trying-squares



J RICHARDS. Trying Square.

Patented Jany 26, 1864.

Jgyo".

Invemtar:

W'otnesses: i wzll.

Lilhograyher. Waihinginn. D. cv

. UNITED STATES PATENT OFFICE.

JOHN RICHARDS, OF COLUMBUS, OHIO.

IMPROVEMENT IN TRYING-SQUARES.

Specification forming part of Lclters Patent No. 4 3,396, dated January26, ISM.

this specification, in which- Figure 1 is a side view of my invention,showing the blade and its pointer in three positions. Fig. 2 is an edgeView of Fig. 1. Figs. 3, 4, 5, and 6 represent modifications of Fig. 1.

Similar letters of reference indicate corresponding parts in the severalfigures.

"Wood-workers employ in their business a small instrument which they usein dressing stuff for determining when they have brought the edge of apiece to a right angle with one or the other of its sides. This tool iscalled a trying-square, and is used by applying it to the stuff andlooking with one eye along its edge. If a space is seen beneath theblade of the square, the edge is not true. If the edge of the blade andthe edge of its head or stock fit closely against the two surfaces ofthe piece of stuff, the piece is called true, and requires no furtherdressing.

The object of my invention is to construct an instrument in such mannerthat it will indicate the angle of the edge of a piece of stuff, andalso indicate when this angle is a right angle,without requiring theworkman to raise the piece of stuff from the bench or to stoop to sightalong its edge, as will be hereinafter de- .scribed.

To enable others skilled in the art to fully understand my invention, Iwill proceed'to describe its construction and operation.

In the accompanying drawings, a represents the head or stock of theinstrument,which may be made of wood, metal, or of both wood andmetal,at the option of the maker. This head a should be made with itsinner edge, a, straight, and,ifdesirable,parallel withtheopposite edge,as shown in Fig.1. To one corner of this head asay at i-I pivot theblade b, which has one straight edge,- b, and a pointed finger, a,formed 011 it that projects out from the end of head a a suitabledistance to form a pointer for indicating the position of the blade I),as will be hereinafter described.

In the instrument represented in Fig. 1 I

use a tapering pointed finger, d, which is fixed to or which may form apart of the head a for indicating the position of the blade I) withreference to the straight edge a. This fixed finger d is of the samelength and shape as finger 0, so that when the blade b is in theposition indicated in full red lines, Fig.1,the two points will bebrought together, as shown in Fig. 2.

A steel V-spring, g, is suitably secured at one end to the edge plate aof the head a and inserted at the other end into a notch, e, which iscut in the lower edge of the rear part of the pivoted blade I), as shownin Fig. 1. This spring g is suitably recessed into the head a, entirelyout of sight and out of the way, and its office is to force the blade 2)down on the shoulder of the edge plate a, so that the edge I) of thisblade will form an acute angle with the edge a of the head a, as shownin Fig. 1, where I have represented the instrument applied to a piece ofstuff which is not true.

The extreme point of the fixed finger d should be so located withreference to the position of the point of the movable finger 0 that whenthe two edges a b are exactly at right angles to each other the pointsof the two fingers will be together or in the same line, and when thepoints are not thus together the space between them will indicate theextent of variation of the two edges a b from a right angle.

It will be seen from the above description that the spring 9 will yieldand allow the blade I) to adapt itself to the angle of the stuffto whichthe instrument is applied, and that when the instrument is removed fromthe stuff this spring will return the blade I) to its original positionagainst the shoulder of the edge plate a. This spring will also allowthe finger c to be moved from one side to the other of the fixed fingerd, as indicated in Fig. 1, so that the instrument isadapted to the'edgesof pieces of stuff which bevel either to the right or to the left.

In Figs. 3, 4, and 5 I have represented several modifications of theinstrument of Fig. 1, in all of which it will be seen that the bladewhich is applied to the stuff to be dressed is movable and pivoted tothe head of the instrument in such manner that this blade will yield andaccommodate itself to the edges of stuff which may be true or more orless beveled, and at the same time indicate,eitl1er by the stock or heador a fixed plate applied to the head, a true angle (right angle) or anydeviation from such angle.

I do not desire to limit myself to the form and proportions of theinstrument represented in Fig. 1, and described in the body of thisspecification, as this form may be greatly changed without departingfrom the principle of the invention which is embodied in the instrumentabove described.

Having thus described the nature of my inventio11,what I claim as new,and desire to se cure by Letters Patent, is-

1. A tryingsquare constructed with a movable blade or its equivalent,substantially as and for the purposes described.

scribed.

JOHN RICHARDS.

\Vitnesses:

W. H. DUANE, W. C. HARD.

